Association between depressive symptoms and 25-hydroxyvitamin D in middle-aged and elderly Chinese

Background: Vitamin D deficiency is recently speculated to play a role in the development of depression. Nevertheless, few studies have explored the association between blood 25-hydroxyvitamin D [25(OH)D] concentrations and depression in the general population. Therefore, we aimed to determine this association in middle-aged and elderly Chinese. Methods: We conducted a population-based cross-sectional study in 2005 in Beijing and Shanghai, China. Participants included 3262 community residents aged 50-70. Depressive symptoms were defined as a Center for Epidemiological Studies of Depression Scale (CES-D) score of 16 or higher. Circulating 25(OH)D concentrations were measured by radioimmunoassay. Results: The prevalence of depressive symptoms was lower in the top tertile of 25(OH)D concentrations compared to the lowest tertile (7.2% vs. 11.1%) in the study population (odds ratio, 0.62; 95% confidence interval, 0.46-0.83; P for trend = 0.002). This association was substantially attenuated after controlling for various confounding factors, and disappeared after including geographic location in the model. Stratified analysis by location did not find any association between depressive symptoms and 25(OH)D levels among participants from either Beijing or Shanghai. Limitations: Due to the cross-sectional study design, causal relation remains unknown. Conclusions: Depressive symptoms are not associated with 25(OH)D concentrations in middle-aged and elderly Chinese. Further prospective studies are required to determine whether they are correlated.